<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // 需求：打印一行5个小星星。
        console.log("*****");

        // 字符串拼接的方式
        let start = '';
        for (let i = 0; i < 5; i++) {
            start = start + "*";
        }
        console.log(start);

        // 打印 4 行， 每行 5 个小星星
        for (let i = 0; i < 4; i++) {
            let start = '';
            for (let j = 0; j < 5; j++) {
                start = start + "*";
            }
            console.log(start);
        }
        // 让用户决定打印几行，几列小星星。
    </script>
</body>
</html>